Navigation system with sign assistance

ABSTRACT

A feature provided by a navigation system or other device whereby additional information about roadside signs can be provided to a driver of a vehicle while traveling along a road. The additional information may be provided automatically or in response to a request from the driver. The additional information may include a translation of the sign text into a selected language, supplementary information about the subject matter of the sign, commercial information about the subject matter of the sign, or other kinds of information. In one embodiment, the additional information is contained in a database that includes data identifying locations of roadside signs and additional information about the roadside signs. Programming in the navigation system or other device determines the location of the vehicle, uses the database to identify one or more roadside signs close to the location of the vehicle, and provides the driver with the additional information about the one or more roadside signs via a user interface.

The present application is a continuation of Ser. No. 09/563,132 filedMay 2, 2000, now U.S. Pat. No. 6,671,615, the entire disclosure of whichis incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a feature provided by a navigationsystem or other device whereby additional information about roadsidesigns can be provided to a driver of a vehicle while traveling along aroad.

Navigation systems are available that provide end users (such as driversand passengers of the vehicles in which the navigation systems areinstalled) with various navigation-related functions and features. Forexample, some navigation systems are able to determine an optimum routeto travel by roads between locations in a geographic region. Using inputfrom the end user, and optionally from equipment that can determineone's physical location (such as a GPS system), a navigation system canexamine various potential routes between two locations to determine anoptimum route to travel from a starting location to a destinationlocation in a geographic region. The navigation system may then providethe end user with information about the optimum route in the form ofguidance that identifies the driving maneuvers required to be taken bythe end user to travel from the starting location to the destinationlocation. The guidance may take the form of visual and/or audioinstructions that are provided along the way as the end user istraveling the route. Some navigation systems are able to show detailedmaps on computer displays outlining routes to destinations, the types ofmaneuvers to be taken at various locations along the routes, locationsof certain types of features, and so on.

In order to provide these and other navigating functions, navigationsystems use geographic data. The geographic data may be in the form ofone or more databases that include data that represent physical featuresin a geographic region The geographic database may include datarepresenting the roads and intersections in a geographic region and alsomay include information relating to the represented roads andintersections in the geographic region, such as turn restrictions atintersections, speed limits along the roads, street names of the variousroads, address ranges along the roads, and so on.

Although navigation systems provide many important features, therecontinues to be room for new features and improvements. One area inwhich there is room for improvement relates to providing assistance withrespect to roadside signs. Regardless of whether a vehicle driver isreceiving route guidance from a navigation system, the vehicle drivershould be paying attention to roadside signs and other traffic-relatedconditions outside the vehicle. Occasionally, a vehicle driver maydesire more information about a sign that he/she has observed whiledriving. There are various reasons why this may occur. One reason isthat the vehicle driver's view of the sign may be obstructed, e.g., byanother vehicle such as a truck. Another reason is that the vehicledriver may not be fluent in the language of the text of the roadsidesign. Still another reason is that the vehicle driver is interested inthe subject matter to which the sign relates and desires moreinformation. Another reason may be that the driver is drowsy ordistracted. Yet another reason may be that the driver is unfamiliar witha symbol on the sign.

Accordingly, there is a need for a feature in a navigation system thatprovides additional information about roadside signs.

SUMMARY OF THE INVENTION

To address these and other objectives, the present invention comprises afeature provided by a navigation system or other device wherebyadditional information about roadside signs can be provided to a driverof a vehicle while traveling along a road. The additional informationmay be provided automatically or in response to a request from thedriver. The additional information may include a translation of the signtext into a selected language, supplementary information about thesubject matter of the sign, commercial information about the subjectmatter of the sign, or other kinds of information. In one embodiment,the additional information is contained in a database that includes dataidentifying locations of roadside signs and additional information aboutthe roadside signs. Programming in the navigation system or other devicedetermines the location of the vehicle, uses the database to identifyone or more roadside signs close to the location of the vehicle, andprovides the driver with the additional information about the one ormore roadside signs via a user interface.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing components of a navigation system thatprovides additional information about roadside signs.

FIG. 2 is an illustration of the navigation system of FIG. 1 installedin a dashboard.

FIG. 3 is a block diagram showing components of the road segment dataincluded in the geographic database of FIG. 1.

FIG. 4 is a block diagram showing components of the road sign dataincluded in the geographic database of FIG. 1.

FIG. 5 illustrates operation of a first embodiment whereby roadside signinformation is provided by the navigation system of FIG. 1 after thevehicle in which the navigation system is installed has passed aroadside sign while traveling along a road.

FIG. 6 is an illustration similar to FIG. 2 and shows operation of asecond embodiment.

FIG. 7 is an illustration similar to FIG. 2 and shows operation of athird embodiment.

FIG. 8 is an illustration similar to FIG. 2 and shows operation of afourth embodiment.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

I. Overview of Navigation System

Referring to FIG. 1, there is a diagram illustrating an exemplaryconfiguration of a navigation system 10. The navigation system 10 is acombination of hardware and software components. In one embodiment, thenavigation system 10 is located in a vehicle 12, such as an automobile.The navigation system 10 includes appropriate positioning systemhardware 14, which in an exemplary embodiment may include a GPS system16 and other sensor equipment 20 that senses the vehicle speed, heading,acceleration, etc. In addition, the navigation system 10 includes anappropriate computer 24, including a CPU 26 and memory 28 as well asother appropriate hardware.

Also included as part of the navigation system 10 is a user interface31. The user interface 31 is coupled to the computer 24. The userinterface 31 includes appropriate means for receiving instructions andinput from a user as well as means for providing information back to theuser. To provide these functions, the user interface 31 includes aninput keypad 36 and possibly other input hardware and software, such asa microphone 37, voice recognition technology, and so on, through whichthe driver (or passenger) can request navigation information andservices. The user interface 31 may also include output hardware andsoftware, such as a display screen 42, speakers 43, speech synthesistechnology, etc., through which the driver or passengers can be providedwith information from the navigation system 10.

All of the components described thus far may be conventional (or otherthan conventional) and the manufacture and use of these components areknown to those of skill in the art. For example, the processor 26 may beof any type used in navigation systems, such as 32-bit processors usinga flat address space, such as a Hitachi SH1, an Intel 80386, an Intel960, a Motorola 68020 (or other processors having similar or greateraddressing space). Processor types other than these, as well asprocessors that may be developed in the future, are also suitable.

FIG. 2 shows components of the user interface 31. In FIG. 2, thenavigation system 10 is installed in a dashboard 33 of the vehicle 12.The components of the user interface 31, including the display 42,speaker 43, and keypad 36, are shown installed in a front panel of thenavigation system 10.

II. Navigation Programming

Referring to FIG. 1, the navigation system 10 includes navigationprogramming 68. The navigation programming 68 may include separateapplications (or subprograms) that provide various navigation-relatedfeature's of the navigation system 10. Included among these applicationsis a vehicle positioning application 69 that receives inputs from thepositioning system hardware 14 and that provides an output thatindicates the vehicle position. Additional applications may be includedfor route calculation, route guidance (wherein detailed directions areprovided for reaching a desired destination), and map display. Otherapplications may also be included. The navigation applications may bewritten in a suitable computer programming language such as C, C++,Java, Visual Basic, etc.

The navigation programming 68 may be stored on a storage device 66 (orROM). During a typical use of the navigation system 10 of FIG. 1, someor all the applications included in the navigation programming 68 areloaded from the ROM 66 into the memory 28 associated with the processor26. The computer 24 receives input from the user interface 31. The inputmay include a request for navigation-related information. Information isobtained from the positioning system hardware 14 indicating a positionof the vehicle 12. The information from the positioning system hardware14 may be used by the navigation programming 68 that is run on theprocessor 26 to determine the location, direction, speed, etc., of thenavigation system 10, and hence the vehicle. The features provided bythese navigation applications are provided to the user (e.g., thevehicle driver) by means of the user interface 31.

III. The Geographic Database

In order to provide navigation features to an end user, the navigationprogramming 68 uses geographic data 70. The geographic data 70 includesinformation about one or more geographic regions or coverage areas. Thegeographic data 70 may be stored in the vehicle 12 or alternatively, thegeographic data 70 may be stored remotely and made available to thenavigation programming 68 in the vehicle 12 through a wirelesscommunication system which may be part of the navigation system 10. Inanother alternative, a portion of the geographic data 70 may be storedin the vehicle 12 and a portion of the geographic data 70 may be storedin a remote location and made available to the navigation programming 68in the vehicle 12 over a wireless communication system from the remotelocation.

In the embodiment shown in FIG. 1, some or all of the geographic data 70are stored on a medium 73 which is located in the vehicle 12.Accordingly, the navigation system 10 includes a drive 74 (or othersuitable peripheral device) into which the medium 73 can be installedand accessed. In one embodiment, the storage medium 73 may be removableand replaceable so that a storage medium with an appropriate data forthe geographic region in which the vehicle is traveling can be used. Inaddition, the storage medium 73 may be replaceable so that data on itcan be updated easily. In one embodiment, the storage medium 73 is aCD-ROM disk. In another alternative embodiment, the storage medium 73may be a PCMCIA card in which case the drive 74 would be substitutedwith a PCMCIA slot. Various other storage media may be used, includingfixed or hard disks, DVD disks or other currently available storagemedia, as well as storage media that may be developed in the future.(Alternatively, the geographic data 70 and the navigation programming 68may be provided on the same storage device or medium.)

In one embodiment, the geographic data are provided by NavigationTechnologies Corporation of Rosemont, Ill. However, it is understoodthat the inventive concepts disclosed herein are not restricted to anyparticular source of data.

Because a navigation system uses data in certain known and expected waysto perform known functions, the geographic data 70 can be organized,structured, and/or arranged in ways that facilitate their use by thenavigation system. Some of the ways that geographic data 70 can be canbe organized, structured, or arranged are described in U.S. Pat. Nos.5,968,109, 5,974,419, and 5,953,722, the entire disclosures of which areincorporated by reference herein.

According to one embodiment, the geographic data 70 used by thenavigation system may be organized into one or more databases 72.Various arrangements can be used for the one or more geographic database72. For example, the geographic data 70 in the one or more databases 72may be organized into separate subsets of data. These subsets mayinclude routing data (used for calculation of routes to desireddestinations), cartographic data (used for map display), maneuver data(used for route guidance), point-of-interest data (for identifyingspecific points of interest, such as hotels, restaurants, museums,stadiums, airports, etc.), name data (identifying the names of roads,places and other features), places (e.g., cities, states, counties), andpostal codes. The geographic data 70 may be defined with different datatypes or with fewer or more data types.

Each subset of the geographic data 70 includes the data and associatedattributes required to perform a particular navigation function butexcludes data and attributes which are not needed to perform thefunction. There is some overlap of data between each of these subsets,with the result that some information may be included in more than onesubset. For example, a data entity representing a road segment in therouting data and a data entity representing the same road segment in thecartographic data may include attributes identifying the nodes locatedat the ends of the road segment. Although this duplication may result ina larger overall data storage requirement, each of the navigationfunctions benefits from the resultant efficiency of handling smalleramounts of data. To permit these types of data to work together, indexesare included as part of the geographic database. The indexes providecross references, search trees, and/or other data finding techniques.

FIG. 3 shows some of the components of the routing data subset 80 of thegeographic database 72. The routing data subset 80 includes a pluralityof road segment data records 82 each of which includes data about aseparate road segment located in the coverage area of the geographicdatabase 72. A road segment record 82 includes a segment ID 82(1) bywhich the data record can be identified in the geographic database 72.The road segment data record 82 includes data 82(2) and 82(3) thatindicate the locations of the endpoints (also referred to as “nodes”) ofthe road segment. The locations of the endpoints may be specified ineither absolute or relative coordinates. In this embodiment, the roadsegment record 82 includes data 82(4) relating to the roadside signslocated along the represented road segment. The data 82(4) include anentry for each roadside sign that is located along the represented roadsegment. Each entry in the roadside sign data 82(4) includes an ID bywhich the represented roadside sign may be identified. Each entry in theroadside sign data 82(4) also includes data indicating a position of therepresented roadside sign. The position data may be expressed as anabsolute or a relative position. In this embodiment, each entry in theroadside sign data 82(4) includes a pointer. The pointer refers to anentry in a collection of sign information data 90. The collection ofsign information data 90 may be a separate subset of the geographic data70 or alternatively, the sign information data 90 may be included as apart of one of the other subsets of data included in the geographicdatabase 72.

In FIG. 3, the sign data 82(4) includes two groups of entries. One groupof entries represents the roadside signs along the represented roadsegment that are observable when traveling along the road segment fromthe right node to the left node and the other group of entriesrepresents the roadside signs along the represented road segment thatare observable when traveling along the road segment from the left nodeto the right node.

The road segment record 82 may also include or be associated with otherdata 82(5) that refer to various other attributes of the representedroad segment. For example, the road segment data record may include dataidentifying what turn restrictions exist at each of the nodes whichcorrespond to intersections at the ends of the road portion representedby the road segment, the name or names by which the represented roadsegment is known, the street address ranges along the represented roadsegment, and so on. The various attributes associated with a roadsegment may be included in a single road segment record, or preferablyare included in more than one type of record which are cross-referencedto each other.

FIG. 4 shows some of the components of the sign information data 90. Thesign information data 90 includes a plurality of entries. In oneembodiment, each entry in the sign information data 90 is associatedwith a separate type of sign. For example, one entry may be associatedwith a “stop sign”, another entry may be associated with a “yield sign”,another entry may be associated with a “railroad crossing sign” and soon. (According to an alternative embodiment, each entry is associatedwith a separate roadside sign.)

Associated with each entry in the sign information data 90 is an ID. TheID is a unique identifier by which the sign type may be identified. Alsoassociated with each entry in the sign data 90 are data indicating thesign meaning in alternative languages. For example, the data indicatingthe sign meaning may be provided in English, French, German, Spanish,Japanese, etc. These data indicating the sign meaning may be provided astext, which can be displayed on the display (42 of FIGS. 1 and 2) oralternatively, the data indicating the sign meaning may be provided asaudio data that can be played over the speaker (42 of FIG. 1). In oneembodiment, both text and audio data are provided. (According to anotheralternative, the data indicating the sign meaning may be stored as atext file and provided audibly using text-to-speech synthesis technologyin a manner known to those of skill in the art.)

In the embodiment of FIG. 4, each entry in the sign data 90 may alsoinclude supplementary data, commercial data, and possibly other data.Each of these types of data is explained in more detail below.

IV. Sign Help Feature

As disclosed in more detail herein, a feature is provided by thenavigation system by which a user of the navigation system can obtaininformation about roadside signs. This feature is provided by a roadsidesign assistance application 99, shown in FIG. 1. The roadside signassistance application 99 is included among the navigation applications68 of the navigation system 10 shown in FIG. 1. When the roadside signassistance 1 feature is invoked, the roadside sign assistance routine 99accesses data from the database 72 about one or more roadside signslocated in the vicinity of the current vehicle position and provides theinformation to the user.

Referring again to FIG. 2, the user of the navigation system 10 caninvoke the roadside sign information feature by appropriate operation ofthe user interface 31 of the navigation system 10. In one embodiment, asign help button 100 is provided on the front panel of the navigationsystem 10. The sign help button 100 is located so that it is easilyaccessible to the navigation system user. Pressing the sign help button100 begins operation of the roadside sign assistance application 99 inthe navigation programming 68.

According to an alternative embodiment, the sign help feature may beactivated by inputting a code into the input keypad 36. According tostill another alternative embodiment, the sign help feature may beactivated by selecting the feature from a selection menu provided on thedisplay screen 42. In yet another alternative, the sign help feature maybe invoked by a voice command.

When the sign help feature is activated, the roadside sign assistanceroutine 99 uses the geographic data 70 to determine which signs arelocated in the vicinity of the vehicle. To perform this function, theroadside sign assistance routine 99 may obtain data indicating thevehicle position from the vehicle positioning application 69, which isincluded in the navigation applications 68 of FIG. 1. According to thisone embodiment, the vehicle positioning application 69 provides anoutput in the form of a series of data structures, each of whichrepresents the current vehicle position at an instant of time. Thevehicle position defined by the vehicle positioning application 69identifies the road segment upon which the vehicle is located, theposition of the vehicle along the identified road segment, and thedirection along the identified road segment that the vehicle is heading.

Using the vehicle position obtained from the vehicle positioningapplication 69, the roadside sign assistance routine 99 identifies theone or more signs located in the vicinity of the vehicle. The roadsidesign assistance routine 99 may perform this function using the sign data82(4) included in the road segment data record 82 that identifies thepositions of the roadside signs that are located along the road segmentupon which the vehicle is located. Upon identifying the roadside signsin the vicinity of the current vehicle position using the entries in thesign data 82(4) in the road segment data record 82, the additionalinformation relating to these identified signs is obtained from the signinformation data 90 using the pointers included in the entries in thesign data 82(4). The appropriate information from the sign informationdata 90 is then provided to the user via the user interface 31.Embodiments showing the different kinds of information that can beprovided to the user are described below.

Embodiment 1

Referring to FIG. 5, the vehicle 12 is shown traveling along a road 114.The vehicle 12 is at a position 110 along the road 114. The vehicle 12has passed a roadside sign 120 that is located at a position 122 alongthe road 114. For any of various reasons, the driver of the vehicle 12,when the vehicle 12 is at the position 110, desires to know whatinformation is contained on the sign 120. For example, the driver's viewof the sign 120 may have been obstructed as the vehicle was at aposition 123 approaching the sign. Alternatively, the sign 120 may havebeen obscured by rain, fog or snow.

When the vehicle 12 is at the location 110, the driver invokes theroadside sign help feature. According to one embodiment described above,the driver may invoke the feature by pressing the help button (100 inFIG. 2) or by other appropriate operation of the user interface 31. Whenthe roadside sign assistance feature is invoked, the roadside signassistance routine 99 obtains the vehicle's current position (from thevehicle positioning application 69) and finds the data associated withthe sign in the vicinity of the current vehicle position (using the signdata 82(4) in the routing data 80 and the sign text data in the signinformation data 90). The roadside sign assistance routine 99 thenprovides the sign information to the user via the user interface 31. Theinformation may be provided audibly using the speaker 43 or visually onthe display 42. In the embodiment of FIG. 5, the sign 120 that thevehicle 12 has passed states “CHRISTOPHER ROAD ¼ MILE AHEAD.” Using theroadside sign assistance feature, the navigation system 10 provides thissame information to the vehicle driver after the vehicle driver haspassed the sign.

(Note that if there is more than one sign in the vicinity of thevehicle, information about the closest sign may be displayed first. Theuser is provided with a means through the user interface to displayinformation about the other signs, e.g., by scrolling back and forth.)

Embodiment 2

FIG. 6 shows another embodiment of the roadside sign assistance feature.FIG. 6 shows the dashboard 33 of the vehicle 12 with the navigationsystem 10 installed therein. Observable by the vehicle driver throughthe windshield of the vehicle 12 is a sign having the text “HISTORICALMARKER EXIT RIGHT ½ MILE AHEAD.” In this example, the driver isFrench-speaking and would desire information about the roadside sign inFrench. According to this alternative embodiment, the driver configuresthe navigation system 10 to provide guidance in French, e.g., by usingan appropriate configuration menu. Then, while driving, the driverinvokes the roadside sign assistance feature (e.g., by pressing the helpbutton 100 or by other appropriate operation of the user interface 31).As in the previous embodiment, when the roadside sign assistanceapplication 99 is invoked, the sign(s) in the vicinity of the vehicleare identified using the data indicating the current vehicle position(from the vehicle positioning application 69) and the data 82(4)indicating the positions of roadside signs from the geographic database72. Using the pointer(s) in the data 82(4), the additional data relatingto the identified roadside signs are obtained from the sign informationdata 90. Then, the roadside sign assistance routine 99 provides thedriver with information about the sign(s) in the vicinity of the currentposition of the vehicle. In this embodiment, because the driver hasconfigured the navigation system to provide guidance in French, theroadside sign application 99 selects the French language data from thesign information data 90 and provides this information to the user.Thus, the navigation system 10 provides the driver with a translation ofthe sign that the driver is observing through the windshield.

Embodiment 3

FIG. 7 shows another embodiment of the roadside sign assistance feature.FIG. 7 shows the dashboard 33 of the vehicle 12 with the navigationsystem 10 installed therein. Observable by the vehicle driver throughthe windshield of the vehicle 12 is a sign having the text “HISTORICALMARKER EXIT RIGHT ½ MILE AHEAD.” In this example, the driver desires toknow additional information about the subject matter of the roadsidesign. According to this alternative embodiment, the driver invokes theroadside sign assistance feature, e.g., by other appropriate operationof the user interface 31. When the roadside sign assistance application99 is invoked, the sign(s) in the vicinity of the vehicle are identifiedusing the data indicating the current vehicle position (from the vehiclepositioning application 69) and the data 82(4) indicating the positionsof roadside signs from the geographic database 72. Using the pointer(s)in the data 82(4), the additional data relating to the identifiedroadside signs are obtained from the sign information data 90. Then, theroadside sign assistance routine 99 provides the driver withsupplementary data about the sign(s) in the vicinity of the currentposition of the vehicle. In this embodiment, because the driver hasrequested supplementary information about roadside sign(s), the roadsidesign application 99 selects the supplementary data associated with thesign(s) from the sign information data 90 and provides thissupplementary information to the user. In this example, thesupplementary information may include historical facts about thehistorical marker referenced on the roadside sign. Thus, the navigationsystem 10 provides the driver with supplementary information about signsin which the driver is interested that the driver is observing throughthe windshield.

Embodiment 4

FIG. 8 shows another embodiment of the roadside sign assistance feature.FIG. 8 shows the dashboard 33 of the vehicle 12 with the navigationsystem 10 installed therein. Observable by the vehicle driver throughthe windshield of the vehicle 12 is a sign having the text “GAS, FOOD,LODGING, NEXT EXIT.” In this example, the driver desires to knowadditional commercial information about the subject matter of theroadside sign. According to this alternative embodiment, the driverinvokes the roadside sign assistance feature, e.g., by other appropriateoperation of the user interface 31. When the driver invokes the roadsidesign assistance feature, the driver indicates that additional commercialinformation about the roadside sign is desired. When the roadside signassistance application 99 is invoked, the sign(s) in the vicinity of thevehicle are identified using the data indicating the current vehicleposition (from the vehicle positioning application 69) and the data82(4) indicating the positions of roadside signs from the geographicdatabase 72. Using the pointer(s) in the data 82(4), the additionalcommercial data relating to the identified roadside signs are obtainedfrom the sign information data 90. Then, the roadside sign assistanceroutine 99 provides the driver with the commercial data about thesign(s) in the vicinity of the current position of the vehicle. In thisembodiment, because the driver has requested commercial informationabout roadside sign(s), the roadside sign application 99 selects thecommercial information data associated with the sign(s) from the signinformation data 90 and provides this commercial information to theuser. In this example, the commercial information may include theidentity, hours of operation, telephone number and other informationabout the facility that is generically referenced on the roadside sign.Thus, the navigation system 10 provides the driver with commercialinformation about signs that would not otherwise be available to thedriver.

Additional Embodiments

In the embodiments described above, the navigation system used ageographic database that included the data indicating the positions ofroadside signs and additional information about the roadside signs. Inan alternative embodiment, roadside signs can include transmitters thattransmit additional information about the subject matter on the signs.The transmitters may be short-range transmitters. Then, the navigationsystem in the vehicle (or other device carried in the vehicle) canreceive the transmissions from the roadside signs and provide theadditional information to the driver. In this embodiment, the driver maybe provided with the option to select the type of additional informationand the language in which the additional information is provided.

In alternative embodiments, the various types of additional data aboutroadside signs can be provided in various combinations. For example, insome alternative embodiments, the navigation system provides only oneadditional type of information about roadside signs. As an example, inone alternative embodiment, only the alternative language of the signtext is provided, but not the supplementary data or the commercial data.In another alternative embodiment, only the supplementary data relatedto the sign text is provided, but not the alternative language data orthe commercial data. In another alternative embodiment, the navigationsystem provides all the above-described additional types of informationabout roadside signs, including alternative languages, supplementarydata, and commercial data.

In alternative embodiments, the supplementary data and the commercialdata can also be provided in alternative languages.

When a navigation system provides more than one type of additionalinformation about roadside signs, the user interface of the navigationsystem provides an appropriate means by which the driver can indicatewhich of the several different types of additional information aboutroadside signs is desired. For example, separate buttons may be providedon the navigation system front panel. Alternatively, the various typesof additional information that are available, e.g., alternativelanguage, supplementary, commercial, can be presented on a menu on thedisplay (43 in FIG. 1) from which the user can make a selection. Inanother alternative, combinations of user inputs can be used to selectthe various types of additional information, e.g., one short press ofthe help button for sign text and two short presses of the help buttonfor supplementary information.

It may occur that there is more than one sign in the vicinity of thevehicle. When this occurs, the user is presented with an option toscroll back and forth among the plurality of roadside signs in thevehicle vicinity, using the keypad or other input means of the userinterface.

In another alternative embodiment, the navigation system can be set in amode in which the additional information associated with all theroadside signs that are encountered as the vehicle is traveling isautomatically presented to the driver. The mode may be used when thedriver wants to be sure not to miss a particular sign or when the driveris curious about the facilities along a road. In an alternative version,the navigation system can be set in a mode in which only thesupplementary information or the commercial information associated withall the roadside signs is presented.

In another alternative embodiment, the navigation system can be set tofilter the additional information about roadside signs that isautomatically presented to the user. The filtering process may be basedon subject matter, business chain, or any other criteria. For example,according to this alternative, the user can select that only informationabout national parks be automatically presented. Then, when a sign aboutnational parks is encountered, the navigation system automaticallypresents the supplementary information or the commercial information tothe user. In another example, the user can select a business chain,e.g., Holiday Inn hotels. Then, when a sign referring to a Holiday Innhotel is encountered, the navigation system automatically presents thesupplementary or commercial information to the user.

The disclosed embodiments can be provided in in-vehicle navigationsystems. The disclosed embodiments can also be implemented on otherplatforms, such as personal computers (including portable computers),hand-held navigation systems, personal digital assistants,PalmPilot®-type devices, wireless telephones, as well as otherelectronic devices.

It is intended that the foregoing detailed description be regarded asillustrative rather than limiting and that it is understood that thefollowing claims including all equivalents are intended to define thescope of the invention.

We claim:
 1. A navigation system comprising: a database that includesdata identifying locations of roadside signs and associated informationabout said roadside signs, wherein said associated information includesat least one of: commercial information, historical information andtranslation of text of the roadside sign into a language other than thelanguage of the roadside sign; programming that determines a location ofa vehicle; programming that uses said database to identify at least oneroadside sign close to said location of said vehicle; and a userinterface that provides to a user of said navigation system saidassociated information from said database about the at least oneroadside sign.
 2. The navigation system of claim 1 wherein said userinterface further comprises: a help button accessible to the user bywhich the user can request the navigation system to provide additionalinformation about roadside signs.
 3. The navigation system of claim 1wherein the roadside sign is a sign that has just been passed by thevehicle.
 4. The navigation system of claim 1 wherein the additionalinformation is provided to the user audibly.
 5. The navigation system ofclaim 1 wherein the associated information is provided automatically. 6.The navigation system of claim 1 wherein said associated informationprovided to the user meets a filter criterion.
 7. The navigation systemof claim 6 wherein the filtering criterion relates to a subject matterof the roadside sign.
 8. A mobile computing platform comprising: a helpbutton accessible to a user by which the user can request the computingplatform to provide information about at least one sign in a vicinity ofa current position of the computing platform; programming that accessesa database that includes information about signs and locations of saidsigns to identify said sign in the vicinity of the computing platform;and a user interface that provides the user with the information aboutsaid sign in the vicinity of the computing platform.
 9. The computingplatform of claim 8 wherein the information about the sign includes atleast one of: commercial information, historical information andtranslation of text of the sign into a language other than the languageof the sign.
 10. The computing platform of claim 8 wherein theinformation is provided to the user audibly.
 11. The computing platformof claim 8 wherein the information is provided to the user on a display.12. The computing platform of claim 8 wherein the information providedto the user meets a filter criterion.
 13. The computing platform ofclaim 12 wherein the filtering criterion relates to a subject matter ofthe sign.
 14. The computing platform of claim 8 wherein said database isremotely located.
 15. A mobile computing platform comprising:programming that accesses a database that includes information aboutsigns and locations of said signs to identify at least one sign in avicinity of a current position of the computing platform; and a userinterface that provides the user with the information about the sign inthe vicinity of the computing platform if a specified filter criterionis satisfied, wherein said filter criterion relates to commercialinformation.
 16. The mobile computing platform of claim 15 wherein saidfiltering criterion is a business chain.
 17. The mobile computingplatform of claim 15 wherein said filtering criterion is a userspecified preference.
 18. The mobile computing platform of claim 15wherein the information is provided automatically.
 19. The mobilecomputing platform of claim 15 wherein the database is remotely located.